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This invention relates to aerosol containers, and more particularly to a 2 piece or 3 piece thin walled, non-barrier type aerosol container.
Thin wall, nonbarrier type, aerosol containers are known in the art. See, for example, U.S. Pat. No. 5,211,317 to Diamond et al., and its reissue Re 35,843. It is a feature of containers built in accordance with the teachings of these patents that the sidewall of the container has a relatively thin thickness. In the Diamond et al. patent and its reissue, the container wall thickness is said to be on the order of 0.004-0.005 inches (0.102 mm-0.127 mm).
In un-pressurized containers, it is often possible to distort the sidewall of the container. The Diamond et al. patents, for example, refer to the sidewall being deflected by as much as xc2xc inch, if a force of as little as 5-10 pounds is applied to the can prior to filling. Additionally, the can, when empty, is said to be easily crushable by hand pressure. However, the cans can be pressurized in a manner so that at 130xc2x0 F. (54.4xc2x0 C.), for example, the pressure does not exceed 120-130 psig. Further, the cans will not burst at one and onehalf times this pressure (180 psig). However, the cans cannot be vacuum filled at a vacuum level greater than 18 inches of Mercury because if they are, the container will collapse.
While there are a number of advantages to a container having thin sidewalls (lower material costs, for example), current thin wall can constructions have drawbacks as well. For example, during handling of the container prior to its being filled, even a moderate amount of force can distort or crush the container. This renders the container unusable and adds to the manufacturing cost. Those skilled in the art will appreciate that moderate amounts of force can be inadvertently applied to the container at any of a number of different points during the handling and manufacture process, even though the process is substantially automated.
It would be advantageous therefore to provide a thin wall aerosol container; however, one which, when unfilled, is not easily distorted and rendered unusable. The container will, when filled, withstand substantial forces without distorting, and meets Department of Transportation (DOT) standards in this regard.
Among the objects of the invention, briefly stated, is a thin wall aerosol container for use in dispensing a fluent material. The container is either of a 2-piece or 3-piece construction, and is either a barrier or non-barrier type container. The container includes a cylindrical can body having a beaded construction. The beading adds significant structural strength to the container and prevents distortion or crushing of the container sidewall when the can is un-pressurized. The container also includes a spray valve assembly for dispensing the fluent material. Because of the increased structural strength created by the beading, the container is not subject to damage during manufacture, while still allowing the manufacturer to realize the savings of a thinner wall construction.
The can is filled both with the fluent material and a propellant. During filling, the container can withstand a vacuum of at least 23 inches of Mercury without collapsing. This allows the can body to be vacuum crimped to the spray valve assembly, simplifying the filling process.
Other objects and features will be in part apparent and in part pointed out hereinafter.